Effect of Maternal Race on Outcome of Preterm Infants in the Military

Abstract

Previous studies suggest that low birth weight black infants have less morbidity and birth-weight-specific mortality during the perinatal period than low birth weight white infants. We studied the effect of maternal race on outcome in preterm infants born at a military hospital that offers free access to obstetric and neonatal care. Between January 1, 1986, and December 31, 1991, data were prospectively collected on all 667 infants delivered at Wilford Hall USAF Medical Center with an estimated gestational age of less than 35 weeks. Three hundred ninety-two white infants and 165 black infants were included in the data analysis. The mean (±SD) birth weight was 1701 ± 65 g for white infants and 1462 ± 66 g for black infants. The mean estimated gestational age was 31.0 ± 3.2 weeks for white infants and 29.9 ± 3.8 weeks for black infants. Preeclampsia was more frequent in black mothers than in white mothers for the entire study population (21% vs 14%), but the birth weight differential between races remained after correction for preeclampsia. There were no significant differences between races in stillbirths, gender, maternal age, maternal transfer status, number of prenatal visits, or percentages of mothers with small-for-gestational-age infants, multiple-gestation infants, prolonged rupture of membranes, or initial prenatal visit during the first trimester. Intraventricular hemorrhage was more frequent in white infants at 27 through 29 weeks estimated gestational age (50% vs 13%). There were no significant differences between the two groups in survival or in the occurrence of severe infraventricular hemorrhage or bronchopulmonary dysplasia. It is concluded that preterm black infants are smaller than preterm white infants when matched for gestational age despite essentially equal utilization of prenatal care. However, maternal race has little direct effect on the survival of liveborn preterm infants in this population.

Integrative Review of Racial Disparities in Perinatal Outcomes Among Beneficiaries of the Military Health System

“…About half (n ¼ 12) of the articles were published more than 20 years ago, from 1983 to 2000 (Adams et al, 1993(Adams et al, , 1994Barfield et al, 1996;Birdsong, 1983;Evans & Rosen, 2000;Greenberg et al 1993;Irwin et al, 1994Irwin et al, , 1996Lombardi et al, 1999;Rawlings & Weir, 1992;Rawlings et al, 1995;Yoder & Young, 1997), and six articles were published in the last 5 years (Engelhardt et al, 2018;Eubanks et al, 2021;Hall et al, 2020;Hamilton et al, 2021;Nash et al, 2019;Nicholson et al, 2020). Most studies had cohort designs using existing data such as medical records, institutional birth logs, hospital discharge records, birth certificates, and databases specific to the MHS (e.g., Department of Defense Birth and Infant Health Registry, Defense Manpower Data Center, Defense Medical Information System, and the MHS Analysis and Reporting Tool (MHS MART), most commonly called M2.…”

“…The sample of one study included only activeduty mothers or fathers (Conlin et al, 2012). One study included only dependent women (Birdsong, 1983), and the remainder had mixed samples of active-duty and civilian beneficiary women (Barfield et al, 1996;Braun et al, 2004; Racial Disparities in Perinatal Outcomes in the MHS Engelhardt et al, 2018;Eubanks et al, 2021;Greenberg et al, 1993;Hamilton et al, 2021;Larsen et al, 2012;Linton & Peterson, 2004a, 2004bLinton et al, 2005;Linton et al, 2004;Rawlings et al, 1995;Rawlings & Weir, 1992;Yoder & Young, 1997). Most authors of studies that included mixed samples did not differentiate results based on active-duty status.…”

“…The samples of eight studies included only Black and White women (Adams et al, 1993(Adams et al, , 1994Barfield et al, 1996;Greenberg et al, 1993;Hamilton et al, 2021;Hatch et al, 2006;Irwin et al, 1994Irwin et al, , 1996. One study included White and minority women, but the authors did not specify the racial group or groups defined as minority (Evans & Rosen, 2000).…”

“…In nine of the included studies, researchers examined preterm birth (Adams et al, 1993 Iobst, S. E., Phillips, A. K., Foster, G., Wasserman, J., and Wilson, C. Conlin et al, 2012;Engelhardt et al, 2018;Evans & Rosen, 2000;Greenberg et al, 1993;Hatch et al, 2006;Rawlings & Weir, 1992;Rawlings et al, 1995;Yoder & Young, 1997). All of these studies had Level 3 evidence, and the quality of the evidence ranged from good (n ¼ 3) to low (n ¼ 6).…”

“…In 10 of the included studies, researchers identified racial disparities related to neonatal size at birth (Barfield et al, 1996;Birdsong, 1983;Braun et al, 2004;Evans & Rosen, 2000;Greenberg et al, 1993;Hall et al, 2020;Lombardi et al, 1999;Rawlings & Weir, 1992;Rawlings et al, 1995;Yoder & Young, 1997). These studies had Level 2 (n ¼ 1) and Level 3 (n ¼ 9) evidence; most were low quality (n ¼ 6), and the remainder were good (n ¼ 3) and high quality (n ¼ 1).…”